czwartek, 19 kwietnia 2012
What is Fiber Channel
Fibre channel is a standard of network technology for data transmissions between computer devices. At first it was used for storage networking - connecting computer servers to shared storage devices and for connecting storage controllers and drives between each other. They can be made of optical fiber cables as well as of copper wires which are twisted. If optical fiber is used a medium, the channel can be very flexible - devices can be as far as ten kilometers apart. For shorter distances the copper cables are used more often. Fibre channel was the first technology to be adopted in storage area networks. Storage area network (SAN) is a network of storage devices that are accessible to servers and allows for resource consolidation and simplifies administration. Fibre channels are faster than SCSI, another type of network technology. They reach gigabyte-speed which is why they have become more common than SCSI in the case of SAN. The SCSI commands can also be transported via fibre channel protocol. Storage area network has been mainly deployed in enterprise storage, which, when compared to the consumer storage, needs higher scalability, higher reliability, better fault tolerance, and requires much more investment.
The large scale of this type of storage involves disaster recovery and advanced backup solutions, which are parts of a large-scale business continuity plan. Fibre channel offers three types of port connections. In limited-connectivity “point to point” topology two devices are connected to each other. “Arbitrated loop” has a set of devices connected to one another in a ring – when one device fails, the whole system is interrupted. The most reliable typology is the “switched fabric”, where all devices are connected to switches which convey the traffic and connection between ports. Here, in the case of one port failure, the functioning of the rest of devices is not affected.